Controlling device for prime movers



Nov. 29, 1949 H. HORNSCHUCH 2,489,778

CONTROLLING DEVICE FOR PRIME MOVERS Filed Nov. 30. 1946 s sheets-sheet 1 SYM' Hls ATTORNEY.'

Nov. 29, 1949 H. HoRNscHucH 2,439,778

CONTROLLING DEVICE FOR PRIME MOVERS Filed NOV. 30. 1946 5 Sheets-Sheet 2 l N V E. NTO R 88 Hanns Horn sclzaca 91. B Y

H15 ATTORNEY.

Nov. 29, 1949 H. HoRNscHucH 2,439,778

CONTROLLING DEVlCE FOR PRIME MOVERS Filed Nov. 30. 194e i s sheets-sheet s l- -llfvl 111 113114 @125 1er .i 1

y H15 ATTORNEY.

Patented Nov. 29, 1949 UNITED .STATES PATENT OFFICE 2,489,118 coN'rnoLLINe DEVICE Foa PRIME MovEns Hanns Hornschuch, Easton, Pa., assignor to Ingersoll-Rand Company, New York, N. Y., :a .corporation of .New Jersey Application November 30, 1194.6, Serial No. 713,253

(Cl. S-35) .11 claims. l

This invention relates to centrifugal pumps,

and more particularly to a controlling device for prime movers serving to drivecentrifugal pumps.

One object of the invention is to prevent the operation of `a centrifugal pump under unfavorable .pressure conditions, as when the -suction pressure is belowa predetermined minimum value or when the pump is insuliiciently primed or improperly vented. Y

-A more -specic `object is toeffect the automatic cutting off of' the power medium to the prime mover whenever anyoi :theaforesaid conditions prevails.

Further objects will be in part obvious and in part pointed out hereinafter.

'In the drawings accompanying this specification and in which similar reference numerals revfer to similar parts,

Figure l is a longitudinal elevation, partly broken away, of a centrifugal pump and its prime mover equipped `with a controlling device constructed in aucordance` with the practice of the invention,

Figure v2 is an elevation, partly in section, of vone'tormof the'invention,

Figure 3 is a transverse view taken through Figure 2 on the line 3-3,

Fig-ure 4 is a Aside elevation, partly broken away, of a modiiied form of the invention taken through Figure v5 -on the line Yliu-4,

Figure 5 is a transverse view taken through Figure 4 onthe `line 5-5, and

Figures 6 and 7 are elevations, in section, taken through Figure 5 on :the lines .6--6 and 'l--1, respectively.

Referring to the drawings and at first more particularly to Figure l, designates a pumping apparatus lcomprising a centrifugal pump 2l, a prime mover 22 and a controlling device 23 constructed in accordance with .the practice of the invention and shown secured to the casing of the pump.

The pump .2l is shown :as having rst and second stage impellers 24 and :25, respectively, and the prime mover 22 is shown, for the Vpurpose of illustration, :as being a .turbine .the wheel 2.5 of which is connected, by suitable shafting 21., to the impellers 24 and vMi. The turbine has the `usual ports and passages 28 for conveying power medium to 'the wheel '26, and the ow vlof power medium is controlled `lby la reciprocatory valve 29 which is actuated by the controlling 5device 23 `for valving the 'power medium to 'the turbine.

VIn the -form shown in Figures "2 and Bfthe con' connected to the valve 29.

trolling device comprises a casing 3U having .a chamber 3i closed at its lower end by a .detachable cover 32 and at its upper end by a plate 33 overlying the casing and secured thereto by ybolts `34. The chamber 3l is Tin constant communication with the discharge side of the pump 2i, in the Apresent instance with the discharge passage-35 for the impeller 24, through a .conduit 36, a recess 3.1 in the casing 30, and an orifice fit opening into the chamber.

The pressure of .the fluid within the chamber S-I'ac-tuates the valve 29 and is transmitted thereto by an actuator 39 in the chamber. In a preferred form, the actuator 39 `comprises a rod 4.0 that extends slidably through .the cover .32 and .through a cylindrical .extension Al, on the inner side of the cover, and has a head 42 the end surface. of which constitutes a pressure .area 43 which is subjected to the pressure in the cham- 'ber 31|.

In order to cushion :the movement of the .ac- .tuator .39 for opening the valve 29 a bellows 44, in fluid tight .eng-agement with the head 42 and the cover 32, is disposed about the `rod 40 and the .extension 4I to. form -a .cushioning chamber 45, and the clearance Mibetween the rod 4B and the extension 4l is .of such area that the air will flow therethrough from the .chamber 45 at a suficientlyv slow rate to .cushion the .down-ward .stroke .of the actuator and thereby assure .the gradual .opening oi the valve 29. The return movement Lof the actuator and ,the valve takes piace comparatively quickly, the .cover 32 being provided with .a `check vvalve mechanism .4 1 of .the ball type which operates in a well Aknown way to admit air into the v:chamber 45.

vThe Arod 4B extends .zexteriorly of the cover 32 .audits lower end engages a stem 48 threadedly lThe opposite end `portion of the rod 48 carries .a nut 49 which acts as an .abutment for .a .seat ,50 engaging an end of a spring :5| the opposite .end of which seats .against a boss `52 on the turbine serving as a guide .for the rod .48.

`Asfwi-ll be apparent, the force of .the spring 5l may be conveniently varied by means ,of the nut 49 and, in practice, the .spring ..51 is so .adjusted that the valve 29 wilfl he opened slightly to .cause operation of the turbine at idiing .speed whenever .a pressure of the val-neef 4suction pressure `exists in the .chamber 3|. ASuch 'opening -movement oi the valve 25 may, if desir-ed, kbe eifected manually by means oi a rod 53 that depends fromthe plate '33 Wherewith it is i-n threaded engagement. l'Ihe rod 53 is normally so positioned that its lower end is spaced from the head @i2 of the actuator and at its opposite end is a hand-wheel whereby the rod may be rotated for endwise adjustment thereof.

Means are provided for preventing the operation of the pump under unfavorable conditions as, for example, when the suction pressure falls below normal, or if the pump is inadvertently cut off from the source of liquid supply, or is unprimed or improperly vented. To this end the casing 30 is provided with a chamber 55 that communicates with the inlet opening 56 of the pump 2| through a conduit 5l and contains a reciprocatory piston 58 having an actuating surface 59 subjected to the pressure in said chamber. Such pressure is yieldingly opposed by a spring 59 interposed between the piston 58 and a tubular spring seat 9| threaded into the plate 33 for varying the force ci the spring 50.

An extension 92 carried by the piston 58 retains the spring 50 in position and extends loosely through the spring seat 3|. These parts are encircled by a bellows 93 interposed between the piston 58 and the plate 33, and the interior of the bellows 63 is in communication with the atmosphere through the spring seat 9 On the opposite` side of the piston 58 is a stem that serves as a valve (ill for communicating the chamber 3i with the chamber 55 whenever the pressure of the fluid acting against the surface 59 falls below the force exerted by the spring 60. The valve 64 is slidable in a bore 95 of a bushing 60 at the lower end of the chamber 55 and has an external annular groove 6l to afford communication between passages G9 and 39 leading, respectively, from relatively spaced points along the length of the bore 55 to the chamber 3| and a channel l5 communicating with the chamber 55, through a port il, and with the lower end of the bore 55 to subject the adjacent end of they fluid from the chamber 3| to the channel 70;

whenever the pressure in the chamber 3| exceeds a certain predetermined maximum value. rThe valve 72 is reciprocable in a bushing 'E3 and has an external annular groove 'lf3 to afford communication between a passage 15, leading from the chamber 3| to the bore 79 containing the valve, and passages 'It and 'i8 leading from the bore i6 to the channel 'l0 and located, respectively, above and below the passage l5.

The lower end of the valve l2 constitutes a pressure surface 'I9 and is subjected to the pressure of the fluid delivered thereto from the chamber 3| by a passage 80. Such pressure is opposed by a spring 9| acting against a spring seat 32 on the other end of the valve 12. The opposite end of the spring 8| engages a spring seat 83 which has a depression 84 for the accommodation of an end of a screw 85 in the plate 33 and having a hand-wheel 96 whereby the screw may be rotated for varying the force of the spring 8l.

Preferably, the chamber 3| is communicated with the chamber 55 through an orifice B1 to maintain the pressure in the chamber 3| at a value proportionate to that of the fluid delivered tc the orice 38, and the pressure in the chamber 3| may, if desired, be controlled manually by means of a needle valve 98 the valve portion 89 of which controls the flow area of a passage 90 leading from the chamber 3| to the channel '10.

The needle valve 88 is supported by the outer wall of the casing 39 and is held fixedly by a lock nut 9 l.

In order to further assure against an excessive pressure within the chamber 3| the casing is provided with a relief passage 92 that leads from said chamber to the chamber 55 and is controlled by a spring-presssed relief valve 93 the casing portion 94 of which is supported by the plate 33.

In practice, and at the beginning of an operating period, all the chambers and passages within the controlling device will be lled with fluid entering them from the suction side of the pump. The valves 94 and 'l2 will then be held in their lowermostpositions by their springs 60 and 8| and the chamber 3| will be in communication with the channel 'i0 through the passages controlled by the valves 34 and l2, and when the chamber 55 is filled the fluid acting against the surface 59 will elevate the valve 64 to cut-off communication between the passages 68 and 69. The fluid then in the chamber 3| and acting against the pressure area |13 will open the valve 29 in the degree required to cause the turbine wheel 26 to operate at idling speed.

Thereafter, as the pressure of the fluid delivered to the chamber 3| by the orifice 38 increases the actuator 39 will be further depressed thereby to open the valve 29 to wider limits. This pressure, acting against the pressure surface 19, will also hold the valve l2 in position to cut-01T communication between the channel 'I0 and the chamber 3|, and whenever it exceeds the predetermined maximum value intended to maintain in the chamber 3| it will shift the valve 12 upwardly to establish communication between the passages i5 and 77. Fluid will then flow from the chamber 3i into the channel i0 until the pressure within the chamber 3| is again reduced to normal and the spring 8| will then restore the valve 'l2 to its ncn-valving position.

In the event that the pressure of the uld acting against the actuating surface 59 falls below the force exerted by the spring 50, as when the suction pressure at the pump falls below normal or the pump loses its prime, the spring 63 will depress the valve 6d and thereby place the passages 63 and 59 in communication with each other through the annular groove 31. Fluid then flows from the chamber 3| through these passages into the channel 'i0 and the pressure within the chamber 3| will thereby be reduced to a Value permitting the spring 5| to quickly shift the valve 29 to the position for cutting off the fluid supply to the turbine.

In the modified form of the invention shown in Figures 4 to 7 inclusive, the casing 95 has a control pressure chamber 96 into which discharge pressure is introduced through an orifice 9'l and a low pressure chamber 93 that communicates with the suction side of the pump 2| through a passage 99. The pressure within the chamber 99 is normally maintained substantially constant by a valve lil@ which controls communication lbetween the chambers 95 and 93. The valve |00 is reciprocable in a bore of a bushing |02 to control passages |93 and |04 spaced along the length of the bushing and, respectively, lead to the chamber 96 and the chamber 98. Communication is afforded between the passages |03 and |04 by an external annular groove |05 in the valve.

One end of the valve |90 constitutes an actuating surface |99 subjected to pressure from the vdischarge side of the pump 2|, say from the dis..

charge passage '5315, i 1an fepd 161.; the

'the casing 195.

Means K ally mounted fon 'a sc'rev'l casing. The holder hasj-'a shoulder 2`Il for engagement With a notch -I is held in engag''ment't "With'by asring |22 connected to the holder aid -tfapin |23 yin the L casing 95. The spring I2^2 exerts-fa Vpull on the holder I I8 for maintaining it in engagement with the pin IIL5, and 'the ivali/" lH93 may be manually rotated, 4to 'effectfsiich'fengagement by means of a spring-pressedrod |24 adaptedfor interlocking engagement vvith the Vvalve and operable from the exterior of thecasi'nig95.

In the Wall of the fcasingfis -a manually operable rotary'trip member |25 -coniprsi'rig'a rod If/Zt` having a hand-wheel '|2"'I,` *forrotating it, carrying ya radially eigite'ridig 'I9 for tilting the holder out Vof 'llgagemlntfwiththe'pin II5.

To the end therme-,holder I Is wm be 'rocked `out of engagement Vvvitli the pin II Eftofrelease the valve IIS 'Whenevrfthepressure lbfth'e huid delivered to the orice 9'I xceedsfaicertain predetermined maxirnum, -the y"casing 'isp'r'ovided With a chamber |2f8 and'fapassage |29 to convey fluid fromthe discharge vside of-thepump to the chamber |23, Vvvh'ence fluidfalso'ows tothe vsurface |95 of thevalve illlll'thrughfa passage |30. At one4 end of the chamber |28 `"is a guide bushing I3I vfor a plunger I|32 having aprssure surface |33 atan 'e'nclftlierel subjected lto the fluid in `the chavmbnIZS; On tthe opposite endI 'fiat "of the piunge'r |32 is fia 'plate 1:34 thetenga'ges Aan end of a spring |535 vs'fhicl'iseats against a plate |36 resting uponjan :adjusting *screw k|31 in the Wall of the 'casing "915.V The v"plate I 34 overlies an arm r|33 f fthe holder fl I8, in spaced relation therewith, and 'seats'against the roof ofthe chamber98. n y u y v Means are providedftoialso tilt -Ithe-holder |I8 out of engagement with Etliei/alve ||3 'in response to a predetermined jniiini'niir'n "suction pressure for relieving the L pressure v'in the chamber 96. To thisfe'nd, a piston |39 'is 'arranged in the chamber `98 to -ovrliefthe var11'f1"|38, and

Athe'undersideofthe piston [39 serves 'as a pressure surface y|49 Whichni's' subjected "tothe pres- 65 sure in the chamber "9'8Ffor holding the piston out of engagement'withvtl'e-am |38. A spring I4I seats againstthe wother nside of the piston |39 and against 'a 'tubular 'seat '|152 threaded, forve'ndvliise adjustment, "in't'o VAa plate |93 covering the 4chamber98. A 1K4 on'the 'piston |39 actil'igfas A.'guideffirtlle'spring |`4I etends loosely through v"the'-:spih'gseat "|42, and

jln 'the :operation of l'the device, @assuming the chambesfthereof 'tb vlllei `rvvi'th @flu-id' at suction pressure f'a-n'd communication between *the Achambers v`9E jand l"98 to be 'cu-'t'off by the valve I I3 in the in rshbtvliniFigue-i of the 'dr'a'w- -ing's, rr-iiisgire'ssure theenambefss will Open valve 29 -s'ligh'ljr 5a-rid lcause Ythe turbine to operate atfi'dling speed. The'niston lI'39vI/ill 'then be fheld out VYof ie t with the holder I|8 by lthe luid in the chamber L98 and the plunger 'YI-32 Vtvill :bel-held thus by the spr-ing I 35. The pressure 'o'f tnelneiutnreafter delivered to the lalb'r 96, bjr nthe `-icle 91, 'fill 'further vde,- pr''ss `t-l'1'e -`acl-,tratar 139 an'd 'open -the valve '129 gradually-to the 'limiting 'po's'ition determined'by -the-s'prlngl. 1

VIn the event that the suction pressure fal beltv "the lr')redet'rmi'ned lfrnini-rhum force exerted by the ls'p'rg MI, said vspring will `thrust lthe piston |39 d'v'vmvvardly against the arll |33 if Vthe holder and difsdrnect litfrom lthe valve I I3. The 'spring 1I I6 v'villythe'n rotate the valve land place Athe`'pas`sage 4'IlIIvin registry `With the passage III. Fluidviillthenflow from the cham 'ber 96 intothe'c'hariberfw izo-reduce the -preslsr'e 'acting 'against the actuator `39, and the spring 5I Will 'shift the 'Valve 2S t0 ycut-off the W'hen 'normal suctih--'prssur'es v:again restored Iin the vchamber 98 -i-t 'will =inove the piston v|99 Iout of the -path of the varm 3l-38 `and the valve '|I3 is 'then rotated l'to its "closed position, by means of 'the springe'pressed rod |24, and the spring |22 will rock *the holder -I'Ii into locking 'engagement with the pin |15.

During the fnormal yopration"of the kpump the plunger |32 "remains inactivebut when the pressure acting -"against the surface '|33 exceeds that exerted by the sprlng'l it Will'shift the plunger fand cause the lplate |34 Ito 'tilt the holder |58 fout of engagement with the valve. The latter 'v'vill 'then assume the openi'position "for reducing -the pressure in the 'chamber 96 and enable the spring 5| to dliickly close the rvalve `29 for cutting off the flovv'f power lIlecli-umto the turbine.

Normally, Ithe pressure f the "fluid in the chamber 96 is maintained"substantially constant by action lof thevalvevlt. This valve is subjected `to the same fluid as the vplunger i132, its spring |91 beingfadjuste'd, however, to yield to 'a different pressure. Thus, YWhenever the pressure in the chamber |528 exceeds the -force of the spring IfIl'I the v'a'lveiI'U willbfe *moved downwardl'y to 'establish 'communication between the passages |03 and 104. The Ipressure 'in the chamber '96 Willtherby' be reduced to the normal Hvalue and thef pring '|01 will then again return -the'valve [9D to its-closed position.

1. In a controlling device for lt1."`1Jr'i1-le irover having a'povver medium controlling member, a pump driven bfth'e prime mover, a casing having a chamber into 4tvliidh saidpu'np'delivs a portion of the fluid pumped thereby, means acting @fessureattachantemettretaieresuied fitte oberste the enf-tronihefmmsr- 2. In a controlling device for a prime mover having a power medium controlling member, a pump driven by the prime mover, a casing having a chamber into which said pump delivers a portion of the fluid pumped thereby, means in the chamber acting responsively to the pressure therein for actuating the controlling member in one direction, resilient means for actuating the controlling member in the opposite direction, and means constantly subjected to the pump suction pressure and acting in response to a predetermined minimum value thereof for effecting a reduction of the pressure in the chamber below the value required to operate the controlling member.

3. In a controlling device for a prime mover having a power medium controlling member, a pump driven by the prime mover, a casing having a chamber into which said pump constantly delivers a portion of the fluid pumped thereby, means acting responsively to the pressure in the chamber for operating the controlling member, valve means acting in response to a predetermined high pressure in the chamber to valve uid therefrom for maintaining a constant pressure in the chamber, and other valve means acting responsively to the pump suction pressure to valve iiuid from the chamber for lowering the pressure therein below the value required to operate the controlling member whenever the suction pressure falls below a predetermined minimum value.

4. In a controlling device for a prime mover having a power medium controlling member, a pump driven by the prime mover, a casing having a chamber into which said pump constantly delivers a portion of the liquid pumped thereby, a piston subjected to the pressure in the chamber for moving the controlling member in a direction to supply power medium to the prime mover, yieldable means constantly tending to move the controlling member in a direction to cut-off the flow of power medium to the prime mover, valve means operating in response to the pressure in the chamber to normally maintain a constant pressure therein, and other valve means acting responsively to the pump suction pressure to eiect a reduction in the pressure within the chamber to a value below the force exerted by the yieldable means whenever the suction pressure reaches a predetermined minimum value.

5. In a controlling device for a prime mover having a power medium controlling member, a pump driven by the prime mover, a casing having a chamber into which the pump constantly delivers a portion of the fluid pumped thereby, a reciprocatory piston actuated by the pressure in the chamber for moving the controlling member in a direction to supply power medium to the prime mover, yieldable means constantly tending to move the controlling member in a direction to reduce the supply of power medium to the prime mover, means for damping the movement of the piston, and means acting in response to a predetermined minimum pump suction pressure for effecting a reduction in the pressure within the chamber below the force exerted by the yieldable means.

6. In a controlling device for a prime mover having a power medium controlling member, a pump driven by the prime mover, a casing having a chamber into which the pump constantly delivers a portion of the fluid pumped thereby, means subjected to the pressure in the chamber for moving the controlling member in a direction for supplying power medium to the prime mover,

yieldable means for moving the controlling member in the opposite direction, means for damping the movement of the first said means, a springpressed valve actuated by a predetermined maximum pressure in the chamber for valving fluid from the chamber to normally maintain a constant pressure in said chamber, and a springpressed valve acting responsively to the suction pressure at the pump to valve fluid from the chamber for reducing the pressure therein below the force exerted by the yieldable means whenever the suction pressure reaches a predetermined minimum value,

7. In a controlling device for a prime mover having a power medium controlling member, a pump driven by the prime mover, a casing having a chamber into which the pump constantly delivers a portion oi the iiuid pumped thereby, means acting responsively to the pressure in the chamber for operating the controlling member, a discharge passage in the casing for the chamber, a valve for controlling the passage, a holder for normally maintaining the valve in position to close the passage, means constantly tending to move the valve into position for opening the passage, and means acting responsively to a preetermined minimum pump suction pressure for actuating the holder to release the valve and thereby enable the second mentioned means to move the Valve into position for opening the passage.

8. In a controlling device for a prime mover having a power medium controlling member, a pump driven by the prime mover, a casing having a chamber into which the pump constantly delivers a portion of the iiuid pumped thereby, an actuator for the controlling member actuated by the pressure in the chamber for supplying power medium to the prime mover, a spring for moving the actuator to reduce the supply of power medium to the prime mover, a discharge passage for the chamber, a valve for controlling the discharge passage normally positioned to preclude the flow of fluid from the chamber through the passage, means for causing the valve to assume a position for opening the passage for effecting a reduction of the pressure in the chamber below the force exerted by the spring whenever the pump suction pressure reaches a predetermined minimum value, and means for causing the valve to assume aposition for opening the passage whenever the pressure oi the iluid discharged by the pump exceeds a certain predetermined value.

9. In a controlling device for a prime mover having a power medium controlling member, a pump driven by the prime mover, a casing having a chamber into which the pump constantly delivers a portion of the iluid pumped thereby, means subjected to the pressure in the chamber for moving the controlling member in a direction to supply power medium to the prime mover, a spring for moving the controlling member in the opposite direction, a discharge passage in the casing for the chamber, a valve for controlling the passage, a holder for normally maintaining the valve in position to close the passage, means constantly tending to move the valve into position to open the passage, means acting responsively to a predetermined minimum pump suction pressure for actuating the holder to release the valve and thereby enable the second mentioned means to move the valve into position for opening the passage to reduce the pressure in the chamber below the force exerted by the spring, and means acting in response to a predetermined maximum pressure of the iiuid supplied to the chamber for actuating the holder to release the valve and thereby enable the second mentioned means to move the valve into position for opening the passage to reduce the pressure in the chamber below the force exerted by the spring.

10. In a controlling device for a prime mover having a power medium controlling member, a pump driven by the prime mover, a casing having a chamber into which the pump constantly delivers a portion of the fluid pumped thereby, an actuator for the controlling member actuated by the pressure in the chamber for supplying power medium to the prime mover, a spring for moving the actuator to reduce such supply of power medium, means acting in response to the pressure of uid discharged by the pump for normally maintaining a constant pressure in the chamber, a discharge passage in the casing for the chamber, a spring-pressed valve for controlling the passage normally positioned to preclude the flow of uid from the chamber through the passage, means for causing the valve to assume a position for opening the passage to effect a reduction of the pressure in the chamber below the force exerted by the spring whenever the pump suction pressure reaches a predetermined minimum value, and means for causing the valve to assume a position for opening the passage whenever the pressure of the uid discharged by the pump exceeds a certain predetermined maximum value.

11. In a controlling device for a prime* mover having a power medium controlling member, a pump driven by the prime mover, a casing having a chamber into which the pump constantly delivers a portion of the fluid pumped thereby, an actuator for the controlling member actuated by Cil the pressure in the chamber for supplying power medium to the prime mover, a spring to move the actuator for reducing the supply of power medium to the prime mover, a discharge passage for the chamber, a rotary valve to control the passage, a spring constantly tending to position the valve for opening the passage, a holder pivotally mounted in the casing to engage the valve for holding said valve in position to close the passage, a spring-pressed piston constantly subjected to pump suction pressure and acting at a predetermined minimum value thereof to disengage the holder from the valve and thereby enable the spring to move the valve into position for opening the passage to effect a reduction of the pressure in the chamber below the force exerted by the first mentioned spring, and a spring-pressed piston constantly subjected to pump discharge pressure and acting at a predetermined maximum value thereof to disengage the holder from the valve and thereby enable the spring to move the valve into position for opening the passage to effect a reduction of the pressure in the chamber below the force exerted by the first mentioned spring.

HANNS HORNSCHUCH.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,621,221 Pogue Mar. 15, 1927 1,834,333 Church s Dec. 1, 1931 

